3 Principal requirements for the system
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1431 – Guidelines for the Approval of Helicopter Facility Foam Fire-Fighting Appliances – (31 May 2012) - Annex – Guidelines for the Approval of Helicopter Facility Foam Fire-Fighting Appliances - 3 Principal requirements for the system

3 Principal requirements for the system

  3.1 The system should be capable of manual release, and may be arranged for automatic release.

  3.2 For helidecks the foam system should contain at least two fixed foam monitors or deck integrated foam nozzles. In addition, at least two hose reels fitted with a foam-making branch pipe and non-collapsible hose sufficient to reach any part of the helideck should be provided. The minimum foam system discharge rate should be determined by multiplying the D-value area by 6 ⋉/min/m2. The minimum foam system discharge rate for deck integrated foam nozzle systems should be determined by multiplying the overall helideck area by 6 ⋉/min/m2. Each monitor should be capable of supplying at least 50 per cent of the minimum foam system discharge rate, but not less than 500 ⋉/min. The minimum discharge rate of each hose reel should be at least 400 ⋉/min. The quantity of foam concentrate should be adequate to allow operation of all connected discharge devices for at least 5 min.

  3.3 Where foam monitors are installed, the distance from the monitor to the farthest extremity of the protected area should be not more than 75 per cent of the monitor throw in still air conditions.

  3.4 For helicopter landing areas, at least two portable foam applicators or two hose reel foam stations should be provided, each capable of discharging a minimum foam solution discharge rate, in accordance with the following table.

Category Helicopter overall length
(D- value) 		Minimum foam solution discharge rate (⋉/min)
H1 up to but not including 15 m 250
H2 from 15 m up to but not including 24 m 500
H3 from 24 m up to but not including 35 m 800

 The quantity of foam concentrate should be adequate to allow operation of all connected discharge devices for at least 10 min. For tankers fitted with a deck foam system, the Administration may consider an alternative arrangement, taking into account the type of foam concentrate to be used.

  3.5 Winching areas should comply with SOLAS regulation II-2/18.2.2.

  3.6 Manual release stations capable of starting necessary pumps and opening required valves, including the fire main system, if used for water supply, should be located at each monitor and hose reel. In addition, a central manual release station should be provided at a protected location. The foam system should be designed to discharge foam with nominal flow and at design pressure from any connected discharge devices within 30 s of activation.

  3.7 Activation of any manual release station should initiate the flow of foam solution to all connected hose reels, monitors, and deck integrated foam nozzles.

  3.8 The system and its components should be designed to withstand ambient temperature changes, vibration, humidity, shock impact and corrosion normally encountered on the open deck, and should be manufactured and tested to the satisfaction of the Administration.

  3.9 A minimum nozzle throw of at least 15 m should be provided with all hose reels and monitors discharging foam simultaneously. The discharge pressure, flow rate, and discharge pattern of deck integrated foam nozzles should be to the satisfaction of the Administration, based on tests that demonstrate the nozzle's capability to extinguish fires involving the largest size helicopter for which the helideck is designed.

  3.10 Monitors, foam-making branch pipes, deck integrated foam nozzles and couplings should be constructed of brass, bronze or stainless steel. Piping, fittings and related components, except gaskets, should be designed to withstand 925ēC.

  3.11 The foam concentrate should be demonstrated effective for extinguishing aviation fuel spill fires and should conform to performance standards not inferior to those acceptable to the Organizationfootnote. Where the foam storage tank is on the exposed deck, freeze protected foam concentrates should be used, if appropriate, for the area of operation.

  3.12 Any equipment installed within the take-off and approach obstacle free sector should not exceed a height of 0.25 m. Any equipment installed in the limited obstacle sector should not exceed the height permitted for objects in this area.

  3.13 All manual release stations, monitor foam stations, hose reel foam stations, hose reels and monitors should be provided with a means of access that does not require travel across the helideck or helicopter landing area.

  3.14 Oscillating monitors, if used, should be preset to discharge foam in a spray pattern and have a means of disengaging the oscillating mechanism to allow rapid conversion to manual operation.

  3.15 If a foam monitor with flow rate up to 1,000 ⋉/min is installed, it should be equipped with an air-aspirating nozzle. If a deck integrated nozzle system is installed, then the additionally installed hose reel should be equipped with an air-aspirating handline nozzles (foam branch pipes). Use of non air-aspirating foam nozzles (on both: monitors and the additional hose reel) is permitted only where foam monitors with a flow rate above 1,000 ⋉/min are installed. If only portable foam applicators or hose reel stations are provided, these should be equipped with an air-aspirating handline nozzles (foam branchpipes).

Parent topic: Annex – Guidelines for the Approval of Helicopter Facility Foam Fire-Fighting Appliances
Copyright 2022 Clasifications Register Group Limited, International Maritime Organization, International Labour Organization or Maritime and Coastguard Agency. All rights reserved. Clasifications Register Group Limited, its affiliates and subsidiaries and their respective officers, employees or agents are, individually and collectively, referred to in this clause as 'Clasifications Register'. Clasifications Register assumes no responsibility and shall not be liable to any person for any loss, damage or expense caused by reliance on the information or advice in this document or howsoever provided, unless that person has signed a contract with the relevant Clasifications Register entity for the provision of this information or advice and in that case any responsibility or liability is exclusively on the terms and conditions set out in that contract.